Process of coating road aggregates



Aug. 7, 1934. K, H. TALBOT 1,969,283v

PROCESS OF COATING ROAD AGGREGATES Filed Nov. 28, 1931 2 Sheets-Sheet l L. @im

Aug- 7, 1934 K. H. TALBOT PROCESS OF COATING' ROAD AGGREGATES Filed NOV. 28. 1931 2 Sheets-Sheet 2 ,Y 0 ....1 l amv ttofcnmp Patented Aug. 7, 1934 FUNITED STATES.

Y 1,969,283" y yrnociiss oF ooA'rINGnoAD seismic.ATLs` Kenneth H. Talbot, Milwaukee, Wis., assigner to National Equipment Corporation, `Milwaukee,

Wis., a'corporation of Delaware Application November 2s,1931,' seri10'. '57%,824

' '17 claims. (ci. 10e-31.)

This invention appertains to the art of preparing road aggregates such as used for the purpose of constructing secondary roads, and primary or other types of roads.

This invention involves-a novel process for the purpose of coating mineral aggregates, such as gravel or the like, used iny road construction such as referred to. l l

The primary aim of the invention has been to devise a process of thoroughly coating each individual particle or element of the mineral, or rock, or other aggregata'that constitutes the body of the road to be made, and in the carrying out of the invention a method comprising new steps of coating procedure have been evolved. The method hereof in its broader phase includes the subjectingvof the mass of solid aggregates, as for instance gravel, sand, or the like, to centrifugal force, the forming of a continuously revolving or moving tube of such aggregates by the application of said force, and directing against the individual constituents or particles of the moving aggregates the fluid coating which is to constitute a binder for the aggregates when laid upon the sub-grade J to make the road.

In accordance with the invention it is preferred to apply the coating mixture to the-aggregate materials Yby spraying these in the form of an effective blast spray from within the tube of movinglmaterials.v In otherA words, the spray o-f the coating mixture is applied to the particles of the aggregate materials as the latter are rotated around the spray incident to the application-to they materials of a centrifugal force, previously referred to. e

. 'Ihe process ofV this invention involves subsidiary features of the method utilized including-the defiecting of the movement of the aggregates underthe influence of their centrifugal force acting thereon to bring the aggregates more fully into the range of movement of the spray of coating mixture, yprovision for checking the volume or amount ofaggregates that are being subjected to the action of the coating-mixture, and provision for varying the speed of movement of the coated aggregates obtained in the practice of `the process, from the point at which they are coated to the point of dischargeV thereof fromwhich they are taken to. the site at which they are to be laid uponthe road. f

With the foregoing andother objects in view that will vbe made clear upon reviewing the fol-'- lowing description in conjunction with the accompanying drawings, itis noted that in the drawings there is illustrated a type of machine adapted to be used for the purposes of the process of this invention. But it is not desired. to be restricted to this particular type of machine by which to carry outthe invention, since-variousx machines may be availed of for the Ypurposes of therprocess or methody hereinafter set forth in detail. f

In the accompanying drawings,

Fig. 1 is a side elevation of a machine suitable for .the purpose of practicing the method of the invention;

Fig. 2 is a diagrammatic view charting certainlof the various mechanical parts andy controlling features of-a machine suitableV for carrying out theprocess to be described;

Fig.l 3V is a .cross-sectional View of the drum of the coating machine illustratinggenerally the mode of supporting the same;

Fig..4iis a' fragmentary longitudinal sectional view of the parts generallyV illustrated in Fig. 3;

Fig. 5 is a cross-sectional view of the coating drum or'v barrel, illustrating the Ymounting of the adjustable scraper -coacting'with the inner surface-ofthe drum mor'eclearly; l

Fig. Bis a viewr of'avsomewhat diagrammatic nature-showing' the manner in which the drum rotates andy imparts to the flowing aggregates a centrifugal force that causes these aggregates to be conducted'inan approximately elliptical path of movement forming them into a tube, so to speak, as previously generally mentioned. The View vis taken Vfrom Ithe charge end. v

AThe machine for carrying out the process hereof will be briefly described only. because it represents merely-a preferred' means by which to practice the inventedmethod and other instrumentalities of a nature to function equivalently maybe .restored to, if desired, forthe same purposes.

In the drawings," and' referring especially to Fig. 1,"1 denotes a hopper adapted toA contain aggregates such as used for the making of secondary 'or other roads'. At the bottom of-rthe hopper -will be provided agate or valve, not clearly shown, but Voperablermanually 'to supply the aggregates within the hopper to a suitable conveyor 2fof the belt type; Y 'l'.lie conveyor 2 is pivotally'support'ed at-onevend, as at 3, whilst its opposite yor right hand end is carried by a flexible member 4 of aweighing indicator 5. The purpose of the indicator 5, Whichjdoes not form a part of this invention as'pre'sent'ed in this application, is to enablethe 'operation of the machine in such aV manner as to Vsupply' a uniform or predetermined rquantity of materials passing from the hopper lb'y means ofthe conveyorfZ, to the coating drum 6 of the machine. From the conveyor 2 the aggregate materials pass to a feeding chute '7 rotatively mounted s o that its lower end may enterthe'upper end of the-drum 6 or may be turned into `'a position to supply materials to'a containerorplace other 'than the drum 6. The coating mixture r'is carried in a large storage tank Bwithiri the framework-off the machine, said tank communicating with the pump line by means/of swingable to the outer position illustrated in Fig.y

1 when it is desired to check the volume of ow of the coating mixture from said nozzle. fJoining with the pipe 12 is a lay-pass pipe or conduit,

16 which leads back to the tank 8, and in the length of this conduit 16 isa pressure release valve 17. The upper portion of the drum 6 is carried by trunnions 18 and the lower portion is supported by trunniorrmembers 19 connected with lifting yokes 20 operable by actuating screws 21 having hand whee1s'22. By manipulation of the parts 19 to 22 the lower end of the drum 6 maybe raised and lowered to vary the velocity of movement of the coated aggregates passing through the drum.-

Referring to Figs. 3 to 6 inclusive, it is noted that withinv the drum 6 at its upper portion is mounted a scraper 23 adjustably carried by screw means 24. so that the scraping. edge 23a thereof maybe moved and held in Vproper relation to the inner wall or surfaceof the'drum 6 for purposes to behereafter described. Inthe drum 6 as seen in Fig. 6 is the-spray nozzle 15, previously referredt-o.

WithV an understanding ofthe machine for practicing the purposes hereof, as given above,`

the cycle of operation incident to the method of this invention will now beset forth. The aggregate materials from the hopper 1 pass to the conyeyor 2, are supplied to the feed chute '7, and enter the drum 6 at its upper end portion. The aggregatematerials are preferably dry when they enter the drum and are to becoated with a coating mixture of a bituminous or other suitable nature, as they are operated upon Within the drum. When the aggregate materials enter the drum the latter is in motion, being rotated at a comparatively high velocity, say approximately 60 R. P. M. for a drum of approximately 24 diameter, and in this way motion isimpartedto the mass of the aggregate materials. VThe centrifugal force obtained from the rotating moving drum 6 isimparted to the aggregate materials as they enter the upperend of the drum, the materials being thus lifted by traveling of the drum in its direction of rotation and beingY engaged near the top portionofthe drum by the scraperA 23. The scraper 23 disengages the materials from the inner wall of the drum and `directs them downwardly with a deflecting function somewhat after the manner depicted in Fig. 6, both the aggregate materialsY operated o n in the manner described having moticn imparted thereto, giving to them a substantially-tubular form. That is,

Vthe aggregate*materialsmovein a circular Vpath,

creating the form of a tube of such materials so that` there is aspace surrounded by the path of their movement. In this tube, orin thespace within the moving of aggregate materials, is located the spray nozzle 15 from which, under high pressure, the coating mixtureris sprayed against ythe moving materials surrounding the same and acted on by the drum. =In this way the aggregate materials are coated with great thoroughness and the operation of supplying the materials, coating the same and. discharging them takes place continuously in a ver-y effectivel manner. y'

the massA by -the Acentrifugal force vincident tothe Referring to the diagram illustration of Fig. 2, the control of the process may become readily apparent. l T hecoating mixture is sleenissuing from the nozzle 15 of the pipe line 13. The pressure regulating valve 14 may be opened or closed to control the volume of oil used per unit of time. The bypass valve 17 may be opened or closed to bypass back to the tank a greater or less quantity of the coating or bituminous mixture. The pump 9 is a constant-speed pump and the use of the valve -17 enables variation in the pressure at the nozzle 15. The burner 25 may be utilized for heating the coating mixture for obvious purposes. It is notable that the scraping appliance 23 performs a separate function independently of its scraping action relative to the drum 6. It acts to deflect the Adirection of movement of the mass of materials from the, path they wouldV ordinarily take due to the effect of the centrifugal force thereon, as illustrated in Fig., 6, so as to impart to the particles or individual elements of the materials a special agitation tending to break or separate the particles, and move them independently of the other movement which has been described. In other words, this action might be characterized as a special agitation imparted to the materials that greatly increases the eciency of the machine insofar as the proper coating of the particles of the mass is concerned. f As stated above, the centrifugal force primarilyyimparts zto the mass its tubular form in the nature of a deflective tubular shaft of -rotating or moving particles and since the spray nozzle supplies the coatingmixture under pressure at the point described the coating substance is caused to penetrate the materials by entering the interstices between the particles in such a manner that all the particles are coated effectively over the `whole superficial area thereof. Where the mass of materials is of a finer nature, such as sand or the like, it is evident thatthe employment of the scraping and agitating means 23 is especially important. Therefore, it is clear from the foregoing that the materials of the aggregate are caused to move in a Idened orbitand Whilst they are moving in such orbit there is impartedto the particles of these materials movement relative to each other and during these movements of the particles they are thoroughly coated. .y v Itis tobeborne. in mind that the process of this inventionis susceptible of use for coating aggregates or minerals, or fine particles of ma'- terials of any sort, the process of the invention not being Vconfined obviously to the use thereof in the artvof preparation of aggregates forro'ad purposes alone.` It is notable also that in the practice of the invention, the materials are maintained in their tubular shape so to speak, as they are raised from the'bottom ofthe drum and travel up to the point where they strike themember 23. At this point there is a scattering action so that a portion of the materials may actually be thrown downwardly and outwardly to strike the drum at a point at ther bottom vof its periphery, while other materials because of their movement within the mass as the material strikes the cutoff or scraper blade 23, are thrown downwardly and inwardlysothat they. strike the periphery of the drum above the lowestpoint of the path of movement.V In other words, the effect of the blade or scraper member 23 is to deect the shape ofthe-tubular form imparted to movement of the drum,y j

'I'he method of moving the materials as above described is important and makes for the uniformity of coating so desirable as a result of the practice of my process. Moreover, the manner of scattering the materials to a certain extent in their centrifugal movement alfords very effective results as regards the action of the spray of the coating material because said spray is thus enabled to coat the surface of the individual particles of the materials. Following the action of spraying incident to my process, there is the additional action of rubbing of particle on particle thus distributing the fluid coating by so domg.

Having thus described my invention, what I claims as new and desire to secure by Letters Patent of the United States is:

1. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, and coating the materials with a coating substance applied to such moving mass and particles thereof.

2. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, spraying a coating mixture upon the mass as it moves, and causing advancing of the mass in the direction of its axis.

3. The method of treating road aggregate materials which comprises imparting to the materials motion forming them intoa moving tubular mass, and applying a coating mixture to the mass from a point surrounded by the moving materials thereof.

4. The method of treating road aggregate materials which comprisesfimparting to the materials motion forming them into a moving tubular mass, and applying a coating mixture to the mass from a point surrounded by the moving materials thereof while advancing the mass in the direction of its axis of movement.

5. The method of treating road aggregate materials which comprises subjecting the materials to centrifugal force to cause them to assume the condition of a tubular shaft of moving aggregate particles, and coating them while so moving.

6. The method of treating road aggregate materials which comprises subjecting the materials to centrifugal force to cause them to assume the condition of a tubular shaft of moving aggregate particles, and spraying such particles with a coating mixture from a point within the space surrounded by the materials.

'7. The method of treating road aggregate materials which comprises subjecting rthe materials to centrifugal force to cause them to assume the condition of a tubular shaft of moving aggregate particles, spraying such particles with a coating mixture from a point Within the space surrounded by the materials, and causing the mass of materials to shift lengthwise of its axis of movement during the spraying operation.

8. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, causing motion of each particle of the materials relative to adjacent particles, and coating the materials with a coating substance applied to such moving mass and particles thereof.

9. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, applying friction to certain particles of the mass to impart movement thereto and create movement of those adjacent particles contacting therewith, and coating the materials with a coating substance applied to such moving mass and particles thereof.

10. The method of treating road aggregate materials which comprises subjecting the materials to centrifugal force causing said materials to assume and form a hollow moving mass, and applying to the materials a coating substance while so moving.

11. The method of treating road aggregate materials which comprises subjecting the materials to centrifugal force causing said materials to assume and form a hollow moving mass, causing agitation of the materials separate from their movement by the centrifugal force, and applying to the materials a coating substance while so moving.

12. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, agitating the particles of the moving tubular mass, and coating the materials with a coating substance applied to such moving mass and particles thereof.

13. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, applying a coating mixture to the mass from a point surrounded by the moving materials thereof, and agitating the particles of the mass additional to their movement in their tubular arrangement.

14. The method of treating road aggregate materials which comprises imparting to the materials motion in a dened closed orbit, subjecting the materials at such time to such movement as to cause motion of the particles thereof relatively to each other, and coating the particles of the materials whilst being subjected to the said movement.

15. The method of treating road aggregate materials which comprises imparting to the materials motion in a delned closed orbit, subjecting the materials at such time to such movement as to cause motion of the particles thereof relatively to each other, and coating the particles of the materials whilst being subjected to the said movement with a coating mixture under pressure causing entrance thereof into the interstices between all particles of materials.

16. The method of treating road aggregate materials which comprises imparting to the materials motion forming them into a moving tubular mass, and applying a coating mixture to the mass from a point surrounded by the moving materials thereof with a positive pressure force acting upon the coating mixture.

17. The method of treating road aggregate materials which comprises subjecting the materials to centrifugal force causing said materials to assume and form a hollow moving mass, causing 140 agitation of the materials separate from their movement by the centrifugal force, applying to the materials a coating substance while so moving, and causing the coating substance to be applied under pressure.

KENNETH H. TALBOT. 

